This 1943 Lincoln cent is struck in steel but is plated with a combination of 90% zinc, 4% antimony and 6% iron. It was recently discovered in the family of a former Philadelphia Mint metallurgist and was the subject of an article in the September 21, 2009 edition of Coin World.

It differs from the regular zinc coated steel cent of this year in that the plating includes antimony and iron. According to researcher Roger Burdette, it is probable that the antimony was added to make the coin darker in color in order to make it less likely to be confused with a dime which, apparently happened often.

This particular piece is listed as RB43-81 in "United States Pattern & Experimental Pieces of WW-II by Roger Burdette. According to the book, experimental 1943 cents were also struck in the following alloys. Descriptions include Roger Burdette numbers.